Difficult as it may be to say Nelson Cruz wasn’t the best free-agent bargain signing of this past winter — he was, and there’s no arguing otherwise — Jason Hammel could give anyone else a run for their money.
Through 12 outings, the former tenth-round draft pick of the Tampa Bay Rays boasts a 0.88 WHIP and 2.53 ERA (second and eleventh-best among qualified big league starters this season, respectively) in a Chicago Cubs rotation that’s shaved off half of an earned run to its staff ERA from last season.
Hammel’s earned-run prevention this season stems mainly from his ability to generate strikeouts (career-best 23.3% K-rate) while limiting the long-ball (career-low 6.8% HR/FB rate), components that have aided to his improved 2.88 FIP and 3.45 xFIP this season (down respectively from 4.93 and 4.56 in 2013).
How has Hammel managed to rack up more strikeouts and limit home runs? He’s commanding his slider.
In 2013, Hammel placed his most frequent offspeed pitch in the upper-half of the zone at a 38.4% rate (well above the 28.8% league average), which was a big reason why opponents accrued a 22.7% HR/FB rate (league average was 10.3%), .448 slugging percentage (also well above the .330 league mark), and 29.2% miss rate (32.8% was league average) against the offering.
This season has been slightly different. Hammel’s slider has been exposed to the upper-half only 26.3% of the time, and results have followed in the form of a 5.0% HR/FB rate, .215 opponent slugging percentage and 41.7% miss rate against it — each of which are significantly improved marks from last season with Baltimore.
FanGraphs claims Hammel’s slider value (per 100 pitches) to this point in the season is 1.93 runs above average, which would be a career-best if the season ended today, and would be a whopping improvement from the career-worst -0.65 runs below average he posted last season with Baltimore.
It’s really no surprise — he’s straying away from the upper-half of the zone, which has limited opponents success rate at clearing fences, and pitching to a more swing-and-miss plane with his slider.
If these improvements continue for a few more weeks at the very least, Theo Epstein could cash in big before the trade deadline.